[Eeglablist] eeglablist Digest, Vol 115, Issue 41

[Pål Gunnar Larsson]

Hi Rick

The practically needed sampling rate depends on what you are looking for. If you look at sold EEG-recording  systems, they default sample 200 /s or 256 /s. This may indicate a population standard. We sample up to 2000/s, but in some cases we even downsample to 100Hz. For visual inspection 5* highest frequncy should be enough to give an acceptable result,as 10* gives a"perfect" match. "Eyeballing" an EEG, gives very little of interest above 30Hz indicating 150Hz to 300Hz as the sampling rate of choice.

The other side of the coin is the dynamics. PL Nunez has looked into that. One of his book is "Neocortical dynamics and Human EEG Rhythms ". He has a paper published in 2000:" Toward a quantitative description of large-scale neocortical dynamic function and EEG " that may be a place to start. Also, his paper on alpha activity may be a good read.

Pål



Hi Pål Gunnar Larsson,
thanks for that information. Do you have a literature source or a detailed information for the practically needed sampling rate in EEG?
Thanks in advance.
Rick

On 22.05.2014 20:31, Pål Gunnar Larsson <pall at ous-hf.no> wrote:
> Remember that EEG is a very dynamic signal. Hence, longer samples is not expected to give better information as the signal changes within the sample window. However, increasing the sampling rate, increases the information. According to Nyquist you will be able to reconstruct a signal if you sample faster than the double of the highest frequency in the signal. However, that is when the signal is stable (EEG is not) and the sample is infinite long. Practically you will often end up sampling 5-10 time the highest frequency in biological signals.

not sensitive